Add class / device portability code. Two autoconf tests

were added to cover the 3 possible APIs from 2.6.9 to
2.6.26.  We attempt to use the newest interfaces and if
not available fallback to the oldest.  This a rework of
some changes proposed by Ricardo for RHEL4.



git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@150 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c

8 files changed, 103 insertions, 44 deletions

diff --git a/autoconf/spl-build.m4 b/autoconf/spl-build.m4
index b311902e9..cb782f9d4 100644
--- a/autoconf/spl-build.m4
+++ b/autoconf/spl-build.m4
@@ -457,3 +457,31 @@ AC_DEFUN([SPL_AC_FLS64],
                AC_MSG_RESULT(no)
        ])
 ])
+
+dnl #
+dnl # 2.6.18 API change, check whether device_create() is available.
+dnl # Device_create() was introduced in 2.6.18 and depricated 
+dnl # class_device_create() which was fully removed in 2.6.26.
+dnl #
+AC_DEFUN([SPL_AC_DEVICE_CREATE], [
+	SPL_CHECK_SYMBOL_EXPORT(
+		[device_create],
+		[drivers/base/core.c],
+		[AC_DEFINE(HAVE_DEVICE_CREATE, 1,
+		[device_create() is available])],
+                [])
+])
+
+dnl #
+dnl # 2.6.13 API change, check whether class_device_create() is available.
+dnl # Class_device_create() was introduced in 2.6.13 and depricated
+dnl # class_simple_device_add() which was fully removed in 2.6.13.
+dnl #
+AC_DEFUN([SPL_AC_CLASS_DEVICE_CREATE], [
+	SPL_CHECK_SYMBOL_EXPORT(
+		[class_device_create],
+		[drivers/base/class.c],
+		[AC_DEFINE(HAVE_CLASS_DEVICE_CREATE, 1,
+		[class_device_create() is available])],
+                [])
+])
diff --git a/configure.ac b/configure.ac
index 99d341a66..1e8c4c0f5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -52,6 +52,8 @@ SPL_AC_PATH_IN_NAMEIDATA
 SPL_AC_TASK_CURR
 SPL_AC_CTL_UNNUMBERED
 SPL_AC_FLS64
+SPL_AC_DEVICE_CREATE
+SPL_AC_CLASS_DEVICE_CREATE
 
 TOPDIR=`/bin/pwd`
 
diff --git a/include/spl-device.h b/include/spl-device.h
new file mode 100644
index 000000000..2bbd299b8
--- /dev/null
+++ b/include/spl-device.h
@@ -0,0 +1,53 @@
+#ifndef _SPL_DEVICE_H
+#define _SPL_DEVICE_H
+
+#include <linux/device.h>
+
+/*
+ * Preferred API from 2.6.18 to 2.6.26+
+ */
+#ifdef HAVE_DEVICE_CREATE
+
+typedef struct class			spl_class;
+
+#define spl_class_create(mod, name)	class_create(mod, name)
+#define spl_class_destroy(cls)		class_destroy(cls)
+#define spl_device_create(cls, parent, devt, device, fmt, args...) \
+	device_create(cls, parent, devt, fmt, ## args)
+#define spl_device_destroy(cls, devt)	device_destroy(cls, devt)
+
+/*
+ * Preferred API from 2.6.13 to 2.6.17
+ * Depricated in 2.6.18
+ * Removed in 2.6.26
+ */
+#else
+#ifdef HAVE_CLASS_DEVICE_CREATE
+
+typedef struct class			spl_class;
+
+#define spl_class_create(mod, name)	class_create(mod, name)
+#define spl_class_destroy(cls)		class_destroy(cls)
+#define spl_device_create(cls, parent, devt, device, fmt, args...) \
+	class_device_create(cls, parent, devt, device, fmt, ## args)
+#define spl_device_destroy(cls, devt)	class_device_destroy(cls, devt)
+
+/*
+ * Prefered API from 2.6.0 to 2.6.12
+ * Depricated in 2.6.13
+ * Removed in 2.6.13
+ */
+#else /* Legacy API */
+
+typedef struct class_simple		spl_class;
+
+#define spl_class_create(mod, name)	class_simple_create(mod, name)
+#define spl_class_destroy(cls)		class_simple_destroy(cls)
+#define spl_device_create(cls, parent, devt, device, fmt, args...) \
+	class_simple_device_add(cls, devt, device, fmt, ## args)
+#define spl_device_destroy(cls, devt)	class_simple_device_remove(devt)
+
+#endif
+#endif
+
+#endif /* _SPL_DEVICE_H */
diff --git a/include/splat-ctl.h b/include/splat-ctl.h
index bd7fdb658..7f2c6d94d 100644
--- a/include/splat-ctl.h
+++ b/include/splat-ctl.h
@@ -33,6 +33,7 @@
 
 #define SPLAT_MAJOR			229 /* XXX - Arbitrary */
 #define SPLAT_MINORS                    1
+#define SPLAT_NAME			"splatctl"
 #define SPLAT_DEV			"/dev/splatctl"
 
 #define SPLAT_NAME_SIZE			12
diff --git a/include/sys/sunddi.h b/include/sys/sunddi.h
index a80ae454d..764ae3820 100644
--- a/include/sys/sunddi.h
+++ b/include/sys/sunddi.h
@@ -35,7 +35,7 @@
 #include <linux/fs.h>
 #include <linux/cdev.h>
 #include <linux/list.h>
-#include <linux/device.h>
+#include <spl-device.h>
 
 typedef int ddi_devid_t;
 
@@ -81,7 +81,7 @@ typedef struct dev_info {
 	kmutex_t di_lock;
 	struct dev_ops *di_ops;
 	struct cdev *di_cdev;
-	struct class *di_class;
+	spl_class *di_class;
 	major_t	di_major;
 	minor_t di_minor;
 	dev_t di_dev;
diff --git a/modules/spl/spl-module.c b/modules/spl/spl-module.c
index a1c31e182..19c5db2cd 100644
--- a/modules/spl/spl-module.c
+++ b/modules/spl/spl-module.c
@@ -153,7 +153,7 @@ __ddi_create_minor_node(dev_info_t *di, char *name, int spec_type,
 		RETURN(DDI_FAILURE);
 	}
 
-	di->di_class = class_create(THIS_MODULE, name);
+	di->di_class = spl_class_create(THIS_MODULE, name);
 	if (IS_ERR(di->di_class)) {
                 rc = PTR_ERR(di->di_class);
                 CERROR("Error creating %s class, %d\n", name, rc);
@@ -165,11 +165,11 @@ __ddi_create_minor_node(dev_info_t *di, char *name, int spec_type,
 
 	/* Do not append a 0 to devices with minor nums of 0 */
 	if (di->di_minor == 0) {
-	        class_device_create(di->di_class, NULL, di->di_dev,
-		                    NULL, "%s", name);
+	        spl_device_create(di->di_class, NULL, di->di_dev,
+		                  NULL, "%s", name);
 	} else {
-	        class_device_create(di->di_class, NULL, di->di_dev,
-		                    NULL, "%s%d", name, di->di_minor);
+	        spl_device_create(di->di_class, NULL, di->di_dev,
+		                  NULL, "%s%d", name, di->di_minor);
 	}
 
 	di->di_cdev = cdev;
@@ -188,8 +188,8 @@ static void
 __ddi_remove_minor_node_locked(dev_info_t *di, char *name)
 {
 	if (di->di_class) {
-		class_device_destroy(di->di_class, di->di_dev);
-		class_destroy(di->di_class);
+		spl_device_destroy(di->di_class, di->di_dev);
+		spl_class_destroy(di->di_class);
 
 		di->di_class = NULL;
 		di->di_dev = 0;
diff --git a/modules/splat/splat-ctl.c b/modules/splat/splat-ctl.c
index f29a98dfa..0c8b673d9 100644
--- a/modules/splat/splat-ctl.c
+++ b/modules/splat/splat-ctl.c
@@ -42,18 +42,7 @@
 
 #include "splat-internal.h"
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
-#include <linux/devfs_fs_kernel.h>
-#endif
-
-#include <linux/cdev.h>
-
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
-static struct class_simple *splat_class;
-#else
-static struct class *splat_class;
-#endif
+static spl_class *splat_class;
 static struct list_head splat_module_list;
 static spinlock_t splat_module_lock;
 
@@ -594,7 +583,7 @@ static struct file_operations splat_fops = {
 
 static struct cdev splat_cdev = {
 	.owner  =	THIS_MODULE,
-	.kobj   =	{ .name = "splatctl", },
+	.kobj   =	{ .name = SPLAT_NAME, },
 };
 
 static int __init
@@ -619,7 +608,7 @@ splat_init(void)
 	SPLAT_SUBSYSTEM_INIT(atomic);
 
 	dev = MKDEV(SPLAT_MAJOR, 0);
-        if ((rc = register_chrdev_region(dev, SPLAT_MINORS, "splatctl")))
+        if ((rc = register_chrdev_region(dev, SPLAT_MINORS, SPLAT_NAME)))
 		goto error;
 
 	/* Support for registering a character driver */
@@ -632,11 +621,7 @@ splat_init(void)
 	}
 
 	/* Support for udev make driver info available in sysfs */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
-        splat_class = class_simple_create(THIS_MODULE, "splat");
-#else
-        splat_class = class_create(THIS_MODULE, "splat");
-#endif
+        splat_class = spl_class_create(THIS_MODULE, "splat");
 	if (IS_ERR(splat_class)) {
 		rc = PTR_ERR(splat_class);
 		printk(KERN_ERR "splat: Error creating splat class, %d\n", rc);
@@ -645,13 +630,8 @@ splat_init(void)
 		goto error;
 	}
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
-	class_simple_device_add(splat_class, MKDEV(SPLAT_MAJOR, 0),
-	                        NULL, "splatctl");
-#else
-	class_device_create(splat_class, NULL, MKDEV(SPLAT_MAJOR, 0),
-	                    NULL, "splatctl");
-#endif
+	spl_device_create(splat_class, NULL, MKDEV(SPLAT_MAJOR, 0),
+			  NULL, SPLAT_NAME);
 
 	printk(KERN_INFO "splat: Loaded Solaris Porting LAyer "
 	       "Tests v%s\n", VERSION);
@@ -666,15 +646,8 @@ splat_fini(void)
 {
 	dev_t dev = MKDEV(SPLAT_MAJOR, 0);
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
-        class_simple_device_remove(dev);
-        class_simple_destroy(splat_class);
-        devfs_remove("splat/splatctl");
-        devfs_remove("splat");
-#else
-        class_device_destroy(splat_class, dev);
-        class_destroy(splat_class);
-#endif
+        spl_device_destroy(splat_class, dev);
+        spl_class_destroy(splat_class);
         cdev_del(&splat_cdev);
         unregister_chrdev_region(dev, SPLAT_MINORS);
 
diff --git a/modules/splat/splat-internal.h b/modules/splat/splat-internal.h
index af5fc6e57..8a7447685 100644
--- a/modules/splat/splat-internal.h
+++ b/modules/splat/splat-internal.h
@@ -60,7 +60,9 @@
 #include <sys/types.h>
 #include <sys/kobj.h>
 #include <sys/atomic.h>
+#include <linux/cdev.h>
 
+#include "spl-device.h"
 #include "splat-ctl.h"
 
 #define SPLAT_SUBSYSTEM_INIT(type)                                      \